# Connect Plus to the Polaris vicra

**URL:** <https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461>\
**Category:** Support\
**Tags:** surgical-navigation\
**Created:** [July 1, 2021, 4:07pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461 "2021-07-01T16:07:44Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![Matteo\_Boles](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/matteo_boles/32/10913_2.png) [@Matteo\_Boles](https://discourse.slicer.org/u/Matteo_Boles)\
**Post date:** [July 1, 2021, 4:07pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/1 "2021-07-01T16:07:44Z")

</div>

Hello,  
I am trying to connect the Polaris Vicra to 3D slicer to be able to read the position of the tip of an instrument, but every time I try to connect the Polaris Vicra with Plus I got the following errors:

```auto
|WARNING|2784.624000|SERVER> vtkPlusChannel::GetTrackedFrameListSampled: Frames in the buffer are not available any more at time: 0.672000. Skipping 0.113000 seconds from the recording to catch up. Increase the buffer size or decrease the acquisition rate to avoid this situation.| in :\D\PSNPb\PlusLib\src\PlusDataCollection\vtkPlusChannel.cxx(1089)

|ERROR|2784.825000|SERVER> Unable to retrieve number of scalar components.| in :\D\PSNPb\PlusLib\src\PlusCommon\IO\vtkPlusNrrdSequenceIO.cxx(585)

|ERROR|2784.841000|SERVER> Unable to prepare header| in :\D\PSNPb\PlusLib\src\PlusDataCollection\VirtualDevices\vtkPlusVirtualCapture.cxx(614)

```

I also attach my config file:

```auto
<PlusConfiguration version="2.1">

  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet 
      Name="PlusServer: NDI Polaris tracker with passive markers" 
      Description="Broadcasting tool tracking data through OpenIGTLink
For NDI Polaris passive marker starting kit: Reference (8700339), Stylus (8700340)" />
    <Device
      Id="TrackerDevice"
      Type="PolarisTracker"
      ToolReferenceFrame="Tracker" >
      <DataSources>
        <DataSource Type="Tool" Id="Reference" RomFile="NdiToolDefinitions/8700339.rom" />
        <DataSource Type="Tool" Id="Stylus" RomFile="NdiToolDefinitions/8700340.rom" />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackerStream" >
		  <DataSource Id="Reference"/>
          <DataSource Id="Stylus"/>
        </OutputChannel>
      </OutputChannels>
    </Device>
    <Device
      Id="CaptureDevice"
      Type="VirtualCapture"
      BaseFilename="RecordingTest.igs.nrrd"
      EnableFileCompression="TRUE"
      EnableCapturingOnStart="TRUE" >
      <InputChannels>
        <InputChannel Id="TrackerStream" />
      </InputChannels>
    </Device>    
  </DataCollection>

  <CoordinateDefinitions>
    <Transform From="StylusTip" To="Stylus"
      Matrix="
        1	0	0.000203823	0.0180449
        3.31529e-09	-1	-1.62655e-05	-0.00144002
        0.000203823	1.62655e-05	-1	-88.5321
        0	0	0	1"
       Error="0.554951" Date="012617_105449" />
  </CoordinateDefinitions>

  <PlusOpenIGTLinkServer 
    MaxNumberOfIgtlMessagesToSend="1"
    MaxTimeSpentWithProcessingMs="50"
    ListeningPort="18944"
    SendValidTransformsOnly="true"
    OutputChannelId="TrackerStream" >
    <DefaultClientInfo>
      <MessageTypes>
        <Message Type="TRANSFORM" />
      </MessageTypes>
      <TransformNames>
        <Transform Name="StylusToReference" />
      </TransformNames>
    </DefaultClientInfo>
  </PlusOpenIGTLinkServer>

</PlusConfiguration>

```

Hope anybody can help!

---

<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [July 1, 2021, 4:21pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/3 "2021-07-01T16:21:26Z")

</div>

You can remove the capture device for now (you’ll still be able to record at the client side) and see if you still get errors.

---

<div class="post-metadata">

**Author:** ![Matteo\_Boles](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/matteo_boles/32/10913_2.png) [@Matteo\_Boles](https://discourse.slicer.org/u/Matteo_Boles)\
**Post date:** [July 1, 2021, 4:38pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/4 "2021-07-01T16:38:15Z")

</div>

Now the error is gone but when I go to 3D slicer nothing happen.  
These are the steps that I did in 3D slicer:

1. I created a tranform and named it “StylusToReference” as in the config file
2. I created a needle model that I put as a child of the “StylusToReference” transform
3. I followed the tutorial and I set up OpenIGTLinkIF module as it was described

Now if I am not wrong, when I move the probe seen by the polaris vicra I should also see the needle model move in 3D slicer, right? or I am missing something?

---

<div class="post-metadata">

**Author:** ![Matteo\_Boles](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/matteo_boles/32/10913_2.png) [@Matteo\_Boles](https://discourse.slicer.org/u/Matteo_Boles)\
**Post date:** [July 2, 2021, 7:22am UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/5 "2021-07-02T07:22:55Z")

</div>

I installed:  
PlusApp-2.8.0.20190617-Win32.exe and I have 3D slicer 4.11  
Are they ok?

---

<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [July 2, 2021, 6:32pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/6 "2021-07-02T18:32:05Z")

</div>

Please use the latest Slicer Preview Release and latest Plus Toolkit release.

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<div class="post-metadata">

**Author:** ![YingyiFang](https://avatars.discourse-cdn.com/v4/letter/y/a698b9/32.png) [@YingyiFang](https://discourse.slicer.org/u/YingyiFang)\
**Post date:** [November 7, 2021, 11:19am UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/7 "2021-11-07T11:19:10Z")

</div>

Excuse me,I am also conducting a similar experiment,and I have the same problem with you.May I ask if your problem has been solved?If so,could you please reply me how to solve this problem?Thanks so much!!

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 8, 2021, 2:42am UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/8 "2021-11-08T02:42:15Z")

</div>

See the post that was mark as solution (remove the capture device section from the file).

@Sunderlandkyl @adamrankin If latest Plus version cannot record a tracking-data-only stream then it is a regression that should be fixed. Not urgent, but at least a bug report should be filed.

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<div class="post-metadata">

**Author:** ![Sunderlandkyl](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/sunderlandkyl/32/79987_2.png) [@Sunderlandkyl](https://discourse.slicer.org/u/Sunderlandkyl)\
**Post date:** [November 8, 2021, 4:30pm UTC](https://discourse.slicer.org/t/connect-plus-to-the-polaris-vicra/18461/9 "2021-11-08T16:30:38Z")

</div>

Just tested recording a tracking-data-only data stream (from a data replay device) in the latest release, and it recorded fine.